Git converts CRLF to LF when plaintext files are staged. The existing
copies of the rte_ckeditor Contrib/* sources have therefore already been
converted to LF by git [1]. Initially these files had been copied as CRLF
from the ckeditor4 sources in node_modules by grunt npmcopy.

Now, when `yarn build` is executed, the copy operation is performed again,
which means the files are reverted back to CRLF. Git therefore needs to
perform the CRLF to LF conversion again. (Which itself needs to be
triggered by the developer by staging the changed files)

We do now mimic git`s autocrlf behaviour and replace CRLF by LF in the
files copied from ckeditor Contrib/* folders to prevent the files
from clobbering the `git status` or `git diff` output.

By passing `encoding: null` to the grunt.file.copy options we ensure
that binary files will be copied as is.

Also configure *.svg files to be checked out as LF on all platforms
(namely windows) like we do for ...